Center for Biological Diversity

For Immediate Release, May 7, 2018

Contact: Ryan Shannon, (503) 283-5474 x 407,

Lawsuit Launched to Protect Imperiled Fish in Arizona, New Mexico

Roundtail Chub Denied Protection for Decades, Despite Habitat Destruction

TUCSON, Ariz.— The Center for Biological Diversity today filed a notice of intent to sue the U.S. Fish and Wildlife Service for failing to protect the roundtail chub, a large minnow in Arizona and New Mexico, under the Endangered Species Act.

The Fish and Wildlife Service first identified the chub’s need for protection in 1982, but waited until 2009 to determine that the fish warranted that protection. The Service proposed protection in 2015, but then abruptly withdrew the proposal in 2017 based on flawed science. 

“Everyone, including the Fish and Wildlife Service, knows that the roundtail chub urgently needs help from the Endangered Species Act,” said Ryan Shannon, staff attorney at the Center for Biological Diversity. “Rather than recognize the threats facing this species, the Service ignored the facts and wrongfully denied protections to this once abundant fish.”

The chub faces threats including habitat destruction, invasive species and climate change. But in withdrawing the proposed protection, the Service did not find that any of those many threats to these native fish have abated.

Instead the Service found that the lower Colorado River basin population of roundtail chub, the headwater chub and the endangered Gila chub are not separate species, but rather a single species, the roundtail chub. Rather than analyze whether the combined species still needed protection, however, the Service withdrew protection without explanation. 

“The decision not to protect this fish was driven by politics, not science. Federal officials decided opposition from the Arizona Game and Fish Department mattered more than saving this clearly imperiled species,” said Shannon. “Like most of the Southwest’s native fish, the roundtail chub desperately needs endangered species protection to have any chance at survival.”

The roundtail chub occurs in Arizona and a small portion of New Mexico. Although it was historically found throughout the lower Colorado River basin, the fish has been reduced to a fraction of its historic range and abundance. It was once so widespread that it was an important food source for native peoples. 

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.6 million members and online activists dedicated to the protection of endangered species and wild places.

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